xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

f2fs: fix to add refcount once page is tagged PG_private

Browse Source 
As Gao Xiang reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=202749

f2fs may skip pageout() due to incorrect page reference count.

The problem here is that MM defined the rule [1] very clearly that
once page was set with PG_private flag, we should increment the
refcount in that page, also main flows like pageout(), migrate_page()
will assume there is one additional page reference count if
page_has_private() returns true.

But currently, f2fs won't add/del refcount when changing PG_private
flag. Anyway, f2fs should follow MM's rule to make MM's related flows
running as expected.

[1] https://lore.kernel.org/lkml/2b19b3c4-2bc4-15fa-15cc-27a13e5c7af1@aol.com/

Reported-by: Gao Xiang <gaoxiang25@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Chao Yu
2019-03-06 17:30:59 +08:00
committed by Jaegeuk Kim
parent 25720cc05e
commit 240a59156d
6 changed files with 36 additions and 23 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
fs/f2fs/checkpoint.c
View File

@@ -406,7 +406,7 @@ static int f2fs_set_meta_page_dirty(struct page *page)
if (!PageDirty(page)) {
__set_page_dirty_nobuffers(page);
inc_page_count(F2FS_P_SB(page), F2FS_DIRTY_META);
SetPagePrivate(page);
f2fs_set_page_private(page, 0);
f2fs_trace_pid(page);
return 1;
}
@@ -957,7 +957,7 @@ void f2fs_update_dirty_page(struct inode *inode, struct page *page)
inode_inc_dirty_pages(inode);
spin_unlock(&sbi->inode_lock[type]);
SetPagePrivate(page);
f2fs_set_page_private(page, 0);
f2fs_trace_pid(page);
}